Compute the photoelectric cutoff frequency f₀ = φ/h from the metal work function φ (eV), for photoelectric-effect and quantum-physics exercises.
输入逸出功 φ(eV),求截止频率。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Threshold frequency | ν₀ = W/h | Einstein 1905 |
| Threshold wavelength | λ₀ = hc/W | Photoelectric theory |
| Work function | 2–5 eV typical, Cs 2.1, Pt 6.3 | Photoemission data |
| Emission condition | Emission requires hν > W | Photoelectric criterion |
| Max kinetic energy | K_max = h(ν − ν₀) | Einstein equation |
| Applications | Photocells, PMT, photocathodes | Detector technology |